Helium

Helium is a light element comprised of two protons and two neutrons in its nucleus. Helium is chemically inert.

Atomic mass: 4.002602 g/mol

Chemical symbol: He

Helium-3

Helium-3 is a light isotope of Helium with only one neutron. It is one of only two known isotopes that is stable with more protons than neutrons (the other being Hydrogen). Helium-3 is being studied for potential applications as a nuclear fusion reactor fuel, and it has industrial applications, as well.

In the Universal CenturyGundam universe, a fleet of tanker vessels constantly moves between Jupiter and the inner planets, carrying a cargo of Helium 3.

Control of Lunar Helium-3 resources is a plot device in the satirical science fiction movie Iron Sky.